Die control for cold pressure welding



3 Sheets-Sheet 1 INVENTOR. WILL/AM A. BARNES BY y March 8, 1960 w. A.BARNES DIE CONTROL FOR coLD PRESSURE WELDING Filed Jan. 28, 1959 March8, 1960 vw. A. BARNES l DIE CONTROL FOR COLD PRESSURE WELDING Filed Jan.28, 1959 5 Sheets-Sheet 2 INVENTOR. WILL/UW BR/VES BY @www AITORNEYSMarch 8, 1960 w. A. BARNES 'DIE CONTROL FOR COLD PRESSURE WELDING FiledJan. 28, 1959 3 Sheets-Sheet 3 INVENToR. WILL/AM A. BARNES BY @u m/wf/ATTORNEYS f pieces beyond the 2,927,487 me coNTRoL non conn PRESSUREwnLnnsG William A. Barnes, Utica, N.Y., assigner to Kelsey-Hayes CompanyThis invention relates in general to gripping and forming apparatusintended for cold pressure welding and relates more speciiically tomechanism for controlling the closing action of split die sectionsupon aworkpiece, and to the control of movement of the closed split die towardanother die with a ipressure weld action.

Apparatus for manual pressure welding, wherein die carriage are driventoward one another by manipulation of handle grip members, have nowbecome well 'known by the pressure welding industry. lSuch devicesrequire the workpieces to be individuallyY loaded and securedin`opposed`split die members, and each workpiece is prepared and trimmedwhile heldin-its die, to a :specific projection from the face of thedie. Thereafter-the diesare driven together by a manualoperation-of lthehandle members to cause the unique lateral Vflow Inow known to be thetrue characteristic of cold-'pressure welding.

`Although such Vmanual operation is highly "successful, andis still veryuseful for its -intended purpose and probably will always be so, thereis need f 'or production welding at a faster rate, and there isneed'fo'r welding power capacity of a-human operator. Larger sizeworkpieces arerdiicult'to set'tightly into'a split die holder under thelimitations of presently-known manual operation.

Therefore, a broad object of the present invention is 4to provideopposed split dies adapted r'st `to 'each close upon separate workpiecesand thereafter` closed jtoward one another to drive the workpiecestogether.

A more speciiic object of the present invention 'is 'to provide improveddie space adjustment devices Hcapable of determining the distancebetween dies at` the vbeginning of a work cycle in order to eliminatetheneed for trimming of the wor'ltpiecesto length- Withirespect to thedie faces.

Another object of this invention, 'therefore' is to `provide opposeddies reciprocabletowardandawayfrom one another, with stop pinsdetermining.the rnairirrium separation distance, wherein the stopVvpinsareaxially s'hiftable and have contact surfaces which areadjustable along the die movement path byreason -f "such axialshiftability. Y

This application is a continuationlin-part Vofap'plication for LettersPatent, Serial No. 2, `1957, for Welding.

treadle 16 operating a control link 17.

- dies in order to compensate for'errorsof'die `ture or wearin the dies.v

vFor afull understanding of the present i'nvention-,regference is madevto the Figures yl through 3. in these illustrations, a stationary diecarriage 23- is carried at fundamental concept of die `spacing `devicesand die retaining devices;

Figure3 is a front view of the lheadrshown yin Figure i 1;. and

Figure 4 is a front view Vof a wpress deviceiembodying relativelyvclosable carriage devices' and embodying; fimproved diespacingapparatus as anillus'tration otfa'n yadjustable modification"this invention.

A portable model of a welding machine, whichyhas 'embodied therein thefundamental features' of this invention, is set forth in Figurel'ofthe'drawings This modelis carried and operated by mechanismcontainedwithin a tote housing 10 made portable byl casters-ll.

v A iluid power system is. housed withinthe toteV housing It). A motori2 and hydraulic pump 13 are drawn in dotted outline.y A belt system 14interconnectsgthe two for power transmission. '.'A `four-way valve 15 iscontrolled by the operator of the device through :a `foot Improved coldpressurewelding dies and controlsvfor Ysuch dies according "to thisinventionvare carried-infn head assembly 2t). The assembly 20 isessentially vn small press'. embodied in a C. frame 21.

This particular embodiment of'the invention has been developed`principally for the cold pressure welding of 'metals `It has been foundy.that vsome metals,.`aluminum .and `copper in particular, can be unitedwith an eXoeptionally strong weld without the use off heat or foreignsubstances. .the workpieces tightly and forcingthem together under-strictly controlled conditions. lurgically, are v`now fullydisclosed,in both literature' and -Such welding is; accomplishedlby;fgripping These conditions,A metalissued patents, and is well'understood skilled in this art.` i

The' inventors of the `parent case ofvwhich Vthis'case is`acontinuation-impart lrecognized certain basic concepts of 'spacingdies to avoid the necessityk of interruption of the weld process afteraworkpieceihas Vbeen :gripped by apair of split dies. This inventionprovided an improved means of adjusting the gap between :such

manufac- 4the `upper mouth portion of the C-shaped frame 2L This diecarriage 23 ispreferably a `composite structure embodying a center block`24 sandwiched between side rails 29 and held in the illustratedposition by a clamp- -ing VYboltl. Figure 3 best illustratesinwardlysloping Aslide surfaces in van inverted V relationship` Thesein669,540, ledsluly i Die Movement Controlfor vCold'Pres'surev Otherobjects and a fuller understanding ottheA invention maybe had'byreferring tothe following description and claims, taken inconjunction with the accompanying drawings in which:

Figure 1 is a general illustration in side elevation of l aportablepress Welder embodying a cam driven carf one another.

wardly sloping slidesurfaces are utilizedy asaclosing. cams `upon whichdie halvesfSt) and 51 may ride. vIt will be seen that an upward forceupon dies S0 Yarrd,51-will cause a closingfcam action forcing these die.halves 'toward one another. `Side rails 29, in conjunctionfwith thecenter block 24, provide a guide slotto direct the dies 50 and 51inmovement toward andaway from A bottom die carriage 25 of similarconstructionprovides sloping surfaces 48 and.i9 insa V,rel'ationship toYact as closing cams. Die halves 52 and I53: Aare designed Y toridethese surfaces and close withjrespect to -one .65

another under 'vertical forces. l Y

In the embodiment of the invention shownin theiirst three figures of'the drawings, the dies are heldin tight "contact'with their cam.surfaces, andl resistance `toggclosing of the dies isprovidedbyhairsprings d-andS.

In a uniting of workpieces, such for example as wire,

by cold pressure butt welding, the workpieces are held by dies andforced tightly against one another in such of thedie..spacing'qgzortionl:ot`

. stop pins vof the dies.

a manner that the workpiecesare caused to iiow laterally in surfacecontact under extreme pressure and under confinement. The principles ofcold pressure welding have been well developed. One of the principleswhich has evolved is that the amount of material'available to tlowduring the welding process is very critical.` Too much material willprevent complete closing of the dies and too little will preventcomplete filling of the die cavity. Either event will produce less thansatisfactory results. Since the time of the original basic concept ofthis invention, applicants have discovered through further research thatthe multiple stage welding action as suggested in the parentapplication, Serial No. 669,540 can, in some instances at least,eliminate the requirement for exact spacing of workpieces with respectto t holding dies. Nevertheless, there are many instances where excessmaterial cannot be tolerated and in all instances better results areobtained if an over-abundance of excess material is not achieved.Furthermore, a weld cannot be achieved at all if the material does notproject suiciently from the dies to have material for welding regardlessof whether the over-projection is critical or not. Hence, this inventionis entirely useful regardless of these later developments.

Prior to this invention, the control of the amount of v -materialbetween the two mated split dies has been achieved lby preparing andtrimming the workpiece with respect to the face of the'die after theworkpiece has been clamped in the die, as shown in Barnes patent, SerialNo. 2,779,954. It has been discovered that two dies can be placed in themachine of this invention with the die faces spaced a precise distancewith respect to one another in order to eliminate preparation devices.Workpieces may then be positioned in the dies with their ends intouching relationship. Thenrbecause the dies are properly spacedoriginally, the amount of ma- `terial within the dies willV be withinacceptable range limitation permitting a uniform Weld. The ends must beclean and relatively square, but need not be spaced to the die face asbefore. Furthermore, as suggested above, there are instances in certaindevelopments now discovered that do not even require the ends to becleaned and relatively square. Nevertheless, clean good results .Y ofvertical adjustment.

lare enhanced by the accurate spacing of the dies according to, theconcepts of this invention.

Because the amount of material between vary according to the dies winthe size and shape of a particular Work- 'piece, the spacing between`dies for various workpiece According to this invention,:

sites will be different.

56, 57, 58, and 59, as best illustrated in Figure' 3, Vare employed asback stops to limit the spacing Then, the actual die length can beaccurately calculated to allow just the correct amount of space betweenthe die faces.

Even the most accurate calculations and the most accurate machine workcannot be counted upon to produce absolutely perfect spacing between diefaces which will remain" perfect under operating conditions.Furthermore, some workpieces, particularly when the wor-kpieces aredrawn wire, will vary in size from'piece to piece or from batch to batchof the workpiece material, and hence some adjustment ofthe space betweenthe Accordingly, reference to Figure 4 will reveal an improved diespacing mechanism carrying the basic principles of die spacing forwardin an improved manner.

justable bed 66. A taper wedge 67 provides a degree An adjustment device68 is provided to accurately determine the position of the wedge 67 andthereby accurately determine the vertical adjustment ofthe bed 66.

This particular press device is top actuated. A guide 81 is provided toguide a ram 82 which in turn is driven through a fixed reciprocal workpath cycle by a hydraulic power unit 83. Springs 84 may be provided toreturn the ram '82 if a conventional one-direction piston and cylinderunit is employed. Generally such piston and cylinder devices, vunlesselaborately equipped, have a fixed travel. Hence, the adjustment of theadjustable bed 66 becomes a desirable feature.

The bed 66 has a Y head 69 providing inwardly sloping cam surfaces 70and 71 substantially identical to the corresponding cam surfaces setforth in Figure l. Likewise die members 72 and 73 are laterallyshiftable along such die surfaces by means of lateral force componentsgenerated through the cam surfaces.

In Figure 2 the stop pins 56 through 59 were described as being the stoppins which determined the maximum die separation.- In this embodiment ofthe invention adjustable die stop pins '75 are provided. Theseadjustable stop pins 7S are conveniently constructed of a central pinmember 76 having a frusto` conical head 77. A bore 79 provides anoperating housing. A,spring 78 within the housing surrounding the pin 76abuts the head 77 and urges the conical head 77 out of the bore 79. Therear part of the pin 76 is threaded and provided with an adjustment locknut 80. Accordingly, rotation of the lock nut Si) will determine theforward projection of the conical head 77. Examination ofthe Figure 4will reveal that the conical side Walls of the head 77 are positioned atsuch an angle that they will always extend in a parallel position withrespect to the back wall of the co-operating die. Hence, the conicalhead may be adjusted forward or backward in order to present aninfinitely adjustable back-stop against which the die may come to rest.Hence, minor variations in workpiece size and in the condition of thedies may be compensated by the adjustable nature of this improved stoppin device.

Although the invention has been described in its ypreferred form with acertain degree of particularity,

and that numerous changes in the details of construction and thecombination and arrangement of parts may be resorted to withoutdeparting from the spirit and the scope of the invention as hereinafterclaimed.

What is claimed is:

A composite jaw, adapted in connection with a supporting member with apair of adjoining angularly disform a part of a machine for cold ofworkpieces, and comprising a pair of side vby side'die sections movableto and from one another, provided vwith cam surfaces in slidingengagement with the cam surfaces of the supporting member respectively,stop means at the rear of each die, each stop means being a pin having aconical end, track means establishing said pin for longitudinaladjustment along a path wherein the conical wall of the end is ad-Figure 4'illustrates the improved adjustable die stop I pin device ofthis invention, as set forth in the environment of an improved pressdevice. The function of the improved press device shown in Figure 4,insofar as cold pressure welding is concerned, is not substantiallydifferent from that shown in Figures 1 through `3.

This press of Figure 4 has a base die bed 65 with an ad Y justablethroughout a range along the path of reciprocation of the associateddie, and means for adjusting the pin along its path. Y

l References Cited in the le of this patent UNITED STATES PATENTS1,331,227 Barnesct al. Feb. `17, 1920 `1,867,288 Thomas July l2, 19322,357,204 1 Joyner Aug. 29, 1944 Barnes Dec. 9, l1958

